Gear Indicator Schematics

The used display has some "short" leds and other "long" leds, shorts leds have half voltage than long leds, thus different resistors have been used for each one to keep the same input current to the PIC, that should not be greather than 18 ma (Microchip declares a maximum output current of 20 ma and maximum input current of 25 ma).

Display is common anode (common positive), so this pin is connected to 5 volt.

7805 IC is tied directly to the metalic chassis of the box to disipate the hot that is produced on it due to voltage drop, from 14 volt to 5 volt.

An input diode has been added to the current input to give the circuit a reverse polarity protection. This diode in addition of the two 10K resistors on the signal inputs, provide the whole reverse protection for the 4 input lines of the box.

Gear input goes from 0 to 5 volt.
Standard voltage values on Suzuki GSXR are:

1st 1.86
2nd 2.36
3rd 3.12
4th 3.73
5th 4.44
6th 4.77
Neutral 5.08

Voltages can be reprogramed for any gearbox by pressing 2 seconds on the switch

Board screenshots: